Method of preparing detergent compositions



United States Patent METHOD OF PREPARING DETERGENT COMPOSITIONS Armin Blumenthal, Johannesburg, Union of South Africa No Drawing. Application January 5, 1954, Serial No. 402,409

8 Claims. (Cl. 252-113 This invention relates to the art of preparing in solid, massive (i. e., tablet, bar, or flake) form non-soapy detergent compositions containing a water-soluble higher alkylaryl sulphonate detergent component, and is concerned more particularly with the provision of an improved binder for such compositions and of an improved method of prethe condensation product of benzene and a chlorinated,

hydrogenated C12C14 Fischer Tropsch hydrocarbon.

The reason for using this special genus of detergents,

the alkyl-aryl sulphonates, is that they are among the most readily available and least expensive anionic surface active agents, and furthermore they offer many other advantages such as great stability toward hydrolysis and the possibility of wide variation in chemical structure and, therefore, in physical properties.

it is well known that non-soapy detergents have certain advantages in use over soaps, inter alia, because while soaps are good cleansers when used in soft water they lose much of their efficiency in hard water and become substantially useless when attempts are made to use them in sea water. Non-soapy detergents, on the other hand, can be effectively used in any type of water.

It is, however, a disadvantage associated with non-soapy detergents that they are normally obtainable only in powder or liquid form, and many attempts have been made to prepare non-soapy detergents in the form of tablets or bars. For a variety of reasons, however, none of these attempts have hitherto proved successful, so far as is known. Sometimes the preparations were too expensive; sometimes they were rejected by the public owing to their poor texture or appearance; and sometimes it was found that the added materials used to produce the tablets or bars tended to reduce the cleansing efficiency of the latter by surrounding and thereby masking the particles of the detergents.

The principal object of the present invention is to overcome these difficulties and to provide non-soapy detergent preparations in the form of tablets or bars which are of good and acceptable texture and feel and which are efficient and agreeable in use.

As a result of prolonged and careful investigations I have found that powdered non-soapy detergents can be produced in the form of tablets or bars of excellent quality by following a stepwise procedure of preparation, in the first step of which procedure the water-soluble higher alkyl-aryl sulphonate, preferably in solid, finely divided form, is incorporated into an initial binding preparation which is liquid when heated and which comprises an at least partially emulsified mixture of a normally solid higher aliphatic acid, e. g., stearic acid, an ester gum and a paraffin wax having a melting point lying between 52 and 60 C.

The ester gum used has a melting point of 95 C. and an acid value of 5-10, and is soluble in aliphatic and aromatic hydrocarbons. Ester gums which have been found operable in the present connection are or consist mostly of the ethyl, methyl and glyceryl esters of rosin acids (chiefly mixtures of abietic, pimaric, sapinic and pyroabietic acids), the estershaving been formed in the presence of a suitable catalyst as well understood.

The above-mentioned initial binding preparation, i. e.,

at least partially emulsified stearic acid, ester gum and parafiin wax mixture represents only a part of the total binding agents used in this process, and the above step is only the first in the complete step-wise procedure. The final binding is caused as the result of the synergistic effect of starch and water-glassadded at a later stage--in relation to the other ingredients, as more fully disclosed hereinbelow.

Various other ingredients may be, and preferably are, i

added to the preparation according to circumstances, and according to the purpose for which the mixture is to be used. Thus, for example, the formula to be used for preparing the improved preparation for toilet use will or may differ from that which will be appropriate for the production of a product for household washing purposes, either in tablet or bar forms in both cases. Variations in the formula may also be desirable depending on the particular non-soapy detergent and other ingredients being used, for example, so as to avoid the above-mentioned surrounding and masking effect.

Examples of formulae for toilet and household tablets or bars and the actual process, the method of carrying the invention into effect, are given below, but it should be mentioned that it will be a relatively simple matter for anyone skilled in the art to determine, by one or more preliminary experiments, what is the most favorable formula and method of manufacture to be adopted in any particular case.

Accordingly the invention comprises, inter alia, a method of manufacturing a non-soapy detergent composition in tablet or bar form in which a Water-soluble higher alkyl-aryl sulphonate is incorporated in a heated initial binder which though normally solid is liquid at the temperature of use and which comprises an at least partially emulsified mixture of a normally solid higher aliphatic acid such as stearic acid, an ester gum, and a paraffin wax having a melting point lying between 52 and 60 C. with the addition of other substances, the mixture being allowed to cool and being thereafter formed into bars or tablets.

I prefer to use a solid, e. g., powdered, non-soapy detergent.

The invention of course includes the hereindescribed improved non-soapy detergent compositions in the form of tablets or bars. It is necessary to add to the mixture of fatty acid, parafiin wax and ester gum either a convenient emulsifying agent, such as one of the following, namely, triethanolamine oleate, polyethylene glycol, monoor di-stearate or mono-oleate, propylene. glycol, mono-stearate or mono-oleate, glyceryl mono-stearate, or, preferably, a quantity of an alkaline carbonate, e. g., sodium carbonate, or of an organic base such for example as ethanolamine or other member of the alkylolamine group, either of which tends to combine with the flatty acid, as I have found that the alkaline or organic base salt of the fatty acid in status nascendi tends to act as an emulsifier and to assist in the satisfactory dispersion of the powdered detergent in the binder and thereby also to prevent the particles of the latter from being masked.

I now proceed to refer to other materials which have to be added, or desirably should be added, to the improved preparation according to circumstances or for the purposes to be hereinafter mentioned.

I add one or more filler substances such, for example, as calcium carbonate, kaolin, clay, talc, or finely divided silica sand. These substances increase the bulk of the preparation and in some cases improve the feel and texture of the final tablet or bar. But, mainly, they counteract'to some extent the hygroscopic or sticky properties of the nns0apy detergent andprovided the quantity added is not too greatthey do not, to any material extent, weaken the cleansing capacity of the non-soapy detergent componentof the composition.

I have also found that it is necessary to include starch in the formula as this substance facilitates dispersion of the non-soapy detergent in the binder and also increases the surface activity of the finished product. It has a useful tendency to prevent the particles of nonsoapy detergent from associating into unduly large particles, and it increases the agreeable feel of the final product when in use. These are only some of the advantages to be derived from the use of starch, which is added to the mixture in the form of a cold suspension in water.

I have also found that it is necessary to add a carefully controlled quantity of sodium silicate (water glass) to the preparation. This substance has various useful effects; it is a good emulsifier and binder, and it increases the lathering of the final product. These are only some advantages to be derived from the use of water glass.

It is to be appreciated that in my process, and resulting product, the binding effect is caused as the result of the synergistic effects of the following:

(a) The initial binder, consisting essentially of stearic acid (or equivalent higher aliphatic acid), parafiin wax and ester gum;

(b) Mucilaginous substances produced through the splitting of starch (by heating) into amylose and amylopectin, and through production of sodium am-ylate through reaction with the sodium groups of the water glass (and of the sodium carbonate, when present);

(0) Binding through partial adsorption of the higher aliphatic acid by the starchH bond formation; and

(d) Binding through the water glass, which per se has a binding effect.

Water glass per se and sodium amylate account for the desirable hardness of the final product. Starch contributes to the desirable feel, texture and gloss of the final product.

I now proceed to quote two formulae for a toilet tablet (which formulae are equally suitable for flakes) and one formula for a household washing tablet or bar, respectively, these formulae being given as specific examples illustrative of the invention:

Toilet tablet N0. 1 The following substances in proportions by weight: 15% dodecylbenzene sulphonate (Santomerse 75 conc.) 25% initial binder (see below) 5% sodium carbonate starch 10% talc 5% water glass 30% water Toilet tablet No. 2

The following substances in proportions by weight:

% ,dodecylbenzene sulphonate (Santomersd 75% come.)

% initial binder (see below) 2 /2% triethanolamine 10% starch 10% kaolin 7V2% water glass water The initial binder referred to in the above two toilet tablet formulae consists of the following ingredients:

20 parts by weight stearic acid I part by weight ester gum 4 parts by weight parafiin wax of melting point between 52 and 60 C.

Household washing tablet or bar 16 parts paraffin wax of melting point between 5 260 C. 8 parts stearic acid 1 part ester gum In general, the product of the present invention is composed of the following components, in the ranges recited, the percentages being by weight:

Per cent Higher aliphatic acid 7-20 Paraffin wax of melting point between 52- Ester gum 0.5-2.0 Water-soluble higher alkyl-aryl sulphonate detergent 5-15 Emulsifier 0.5-5.0 Filler 10-20 Starch 5-15 Water glass (sodium silicate) 5-10 Water 25-30 In the matter of the emulsifier component, in case sodium carbonate is used the amount thereof is from 2.5 to 5.0% by weight, while in the case of triethanolamine the amount is from 0.5 to 2.5%. When in lieu of these reactants a conventional pre-formed emulsifying agent is employed the amount thereof is from 2.5 to 5.0%.

I have found that in order toobtain the best results the actual process has to be carried out within a certain method in a definite sequence of stages, and I now proceed to explain the sequence of operations which I have found satisfactory for the preparation of the improved tablets or bars in accordance with the above mentioned formulae.

STAGE 1 I first proceed to prepare the initial binder by melting the stearic acid, ester gum and paraffin wax together at a temperature not exceeding 95 C. while thoroughly stirring the mixture until the bubbles on the surface disappear. The heating may then be stopped and the liquid allowed to cool under continuous stirring until it acquires a creamy consistency. It may then be allowed to cool until it solidifies. I have found it advisable to allow the creamy mixture to stand or mature" for a period of at least seven days as after this period its properties will be found to be superior to those of the freshly made initial binder.

STAGE 2 A water-soluble alkaline acting substance such as an alkaline carbonate or an organic base, or an emulsifier, is dissolved in an appropriate quantity of water and heated to a temperature of about C. The matured initial binder is melted, and is gradually added in liquid form to said aqueous solution with continuous stirring at a temperature of about 80 C. until a creamy shiny mass is produced.

STAGE 3 At this stage and at the approximate temperature recited, the water-soluble higher alkyl-aryl sulphonate is gradually added with continuous stirring until a homogeneous mass is obtained, care being taken to avoid overheating.

STAGE 4 A cold suspension of starch in water is added at this stage to the mixture, with continuous stirring, the temperature being raised to the region of 100 C.

STAGE 6 Water glass is now added with stirring while the temperature is maintained in the region of 100 C. After stirring has been continued for a sufficient time the resulting mass is allowed to cool and tested to ensure the appropriate hardness and texture.

I have found that for the purpose of the present process it is advantageous to use a mixing device which brings about both squeezing and eccentric action.

The further treatment of the mass, such as drying, molding, plodding and the like may follow normal conventional procedure as used in the production of soap, subject to any variations which will be obvious to those skilled in the art of soap manufacture.

In order to facilitate a better understanding of the invention the following more detailed explanation is given, by way of example only, of one method of carrying out the several stages referred to above.

Process for the manufacture of toilet tablet N0. 1

STAGE l.-PRODUCTION OF BINDER lbs. of stearic acid, 1 lb. of ester gum and 4 lbs. of paratfin wax of a melting point lying between 52 and 60 C. are melted together at a temperature not exceeding 95 C. The mixture is stirred thoroughly until the bubbles on the surface disappear, when the heating is interrupted and the liquid is allowed to cool under continuous stirring as described above until it acquires a creamy consistency, when it is allowed to cool by itself until it solidifies. This binder is preferably allowed to stand for at least 7 days before being further used.

STAGE 2 5 lbs. of sodium carbonate are dissolved in 3 gals. lbs.) of water, the temperature being kept at approximately 80 C. The matured initial binder from Stage 1 is melted and gradually added in a liquid state under continuous stirring, at a temperature of about 80 C., until a creamy shiny mass is produced.

STAGE 3 15 lbs. of the water-soluble higher aryl-alkyl sulphonate (e. g., Santomerse 75% cone.), is now continuously stirred into the mixture until a homogeneous mass results. Care should be taken to avoid over-heating.

STAGE 4 10 lbs. of talcum in finely divided form is added to the mixture with continuous stirring. Cooling of the mixture must be avoided.

STAGE 5 A cold suspension of 10 lbs. of starch in 2 gals. of water is prepared and this suspension is gradually added to the mixture with continuous stirring while the temperature is raised to, and maintained in, the region of C., until a pasty, glossy mass is formed.

STAGE 6 At this stage 5 lbs. of water glass are added as a last ingredient while the stirring is continued and the temperature is maintained in the region of 100 C. so as to drive off any surplus water.

It is desirable to test samples of the material as to the texture and other properties of the product on cooling and hardening before removing the charge from the pot.

Once a sample has proved to be satisfactory the charge is removed and the further treatment of the mass, either for the production of tablets or bars, by way of drying, molding, plodding, tabletting and the like, or for the production of flakes, by Way of drying, flaking, milling and the like, may proceed on conventional lines.

The procedure for the preparation of the toilet tablet No. 2 is the same as described in the case of the toilet tablet No. 1 save that in this case 2 /2 lbs. of triethanolamine are used instead of 5 lbs. sodium carbonate; 10 lbs. kaolin are used instead of 10 lbs. talcum; and 7V2 lbs. water glass are used instead of 5 lbs.

The procedure for the preparation of a household washing tablet or bar is the same as that above described in the case of the toilet tablet, save that in this case I add /2--1% carboxymethyl cellulose, or similar product after the sodium carbonate has been added to the binder when it has become glossy and creamy in appearance. Furthermore, I use calcium carbonate.

If desired, a foaming agent may also be added, preferably in the form of a liquid or solution, and the amount of water used in the above formulae may be reduced by the'amount of liquid foaming agent added.

It is to be understood that the recitation, in the above specific examples, of dodecylbenzene sulphonate as the water-soluble higher alkyl-aryl sulphonate component of the composition is illustrative only, and that in lieu thereof there may be substituted an equivalent amount of another. water-soluble higher alkyl-aryl sulphonate such as kerylbenzene sulphonate (e. g., Nacconol NRSF," product of Allied Chemical and Dye Corp.) and similar water-soluble alkyl-aryl sulphonates having an alkyl chain length of from C9 to C16 and wherein the aryl radical is either benzyl or naphthyl.

I claim:

1. Process of producing a non-soapy detergent composition in massive form, which comprises melting together, at an elevated temperature not materially exceeding 100 C., 7 to 20 parts by weight of stearic acid, 2 to 16 parts by weight of a paraifin Wax having a melting point lying between 52 and 60 C., and 0.5 to 2.0 parts by weight of an ester gum, continuing the heating and stirring until the bubble formation ceases, continuing the stirring without heating until the mixture assumes a creamy consistency, maturing the mixture by allowing it to stand for several days, preparing a hot aqueous solution of from 2.5 to 5.0 parts by weight of sodium carbonate, melting the matured mixture and thoroughly dispersing the same in said hot aqueous solution, with stirring, gradually adding to and thoroughly dispersing in the resulting hot partially emulsified mixture 5 to 15 parts by weight of a water-soluble alkyl benzene sulphonate detergent the length of the alkyl chain of which is from C9 to C16, serially incorporating 10 to 20 parts by Weight of an inert filler and an aqueous suspension of 5 to 15 parts by weight of starch into the hot sulphonatecontaining mass, raising the temperature of the mass to approximately 100 C. and dispersing 5 to 15 parts by weight of water glass (sodium silicate) therethrough, and thereafter working up and forming the resulting composition into massive form.

2. Process of producing a non-soapy detergent composition in tablet or bar form, which comprises melting together, at an elevated temperature not materially ex.-

7 ceeding 100 C., 7 to 20 parts by weight of stearic acid, 2 to 16 parts by weight of a paraffin wax having a melting point lying between 52 and 60 C., and 0.5 to 2.0

melting the matured mixture and thoroughly dispersing the same in said hot aqueous solution, with stirring, gradually adding to and thoroughly dispersing in the resulting hot partially emulsified mixture 5 to parts by weight of a water-soluble alkyl benzene sulphonate detergent the length of the alkyl chain of which is from C9 to C16, serially incorporating 10 to parts by weight of an inert filler and an aqueous suspension of 5 to 15 parts by weight of starch into the hot sulphonate-containing mass, raising the temperature of the mass to approximately 100 C. and dispersing 5 to 10 parts by weight of water glass (sodium silicate) therethrough, and thereafter working up and forming the resulting product into tablet or bar form.

3. The process of producing a non-soapy detergent composition in massive form, as defined in claim 1, according to which said composition is worked up and formed into a flaked product.

4. Process of producing a non-soapy detergent composition, in tablet, bar or flake form, which includes the steps of (1) preparing an initial binder composition by melting together from 1440 parts of a higher aliphatic acid, from 4-32 parts of a parafiin wax having a melting point lying between 52 C. and 60 C. and from 1-4 parts of an ester gum, (2) incorporating from 1-10 parts of an emulsifying component in said molten composition, K

(3) homogeneously dispersing from 10-30 parts of a water soluble higher alkyl aryl sulp'honate' detergent throughout said composition, and (4) adding from 10- parts of starch and from 10-20 parts of waterglass (sodium silicate) to said composition and thoroughly incorporating the same, the parts being by weight.

5. Process of producing a non-soapy detergent composition as defined in claim 4, including the additional step of maturing the initial binder composition prior to incorporation of the other components of the composition.

6. Process of producing a non-soapy detergent composition as defined in claim 4, wherein the emulsifying component is an alkaline acting substance of the group consisting of alkali carbonates and water-soluble alkylolamines.

7. Process of producing a non-soapy detergent composition in tablet, bar or fiake form, which comprises melting together, at an elevated temperature not materially exceeding 100 C., with thorough stirring, from 720% of a higher aliphatic acid, from 216% of a paraffin wax having a melting point lying between 52 and C. and from 0.52.0% of an ester gum, continuing the heating and stirring until bubble formation ceases, continumg the stirring without further heating until the mixture assumes a creamy consistency, and maturing the mixture, thereafter melting the mixture and thoroughly dispersing the same in a hot aqueous solution of from 0.55.0% of a water-soluble alkaline acting substance, with stirring, until a hot creamy shiny mass is produced, thereupon gradually adding from 5-15% of a watersoluble higher alkyl aryl sulphonate detergent to and homogeneously dispersing the same in said hot mass, incorporating a filler material if desired and from 5-15% of starch into the hot sulphonate-containing mass, adding from 510% of waterglass (sodium silicate) to and thoroughly incorporating the same in said fillerand starchcontaining mass at an elevated temperature approximating C., and thereafter working up and forming the 1 resulting product into tablet, bar or flake form by conventional soap-making procedure, the percentages being by weight based on the final product.

8. Process of producing a non-soapy detergent composition in massive form, which comprises melting together, at an elevated temperature not materially exceeding 100 C., from 720% of stearic acid, from 2-16% of a parafiin wax having a melting point lying between 52 and 60 C., and from 0.52.0% of an ester gum, continuing the heating and stirring until bubble formation ceases, continuing the stirring without heating until the mixture assumes a creamy consistency, maturing the mixture by allowing it to stand for several days, preparing a hot aqueous solution of from 0.55.0% of an alkaline acting substance of the group consisting of alkali carbonates and alkylolamines, melting the matured mixture and thoroughly dispersing the same in said hot aqueous solution, with stirring, gradually adding to and thoroughly dispersing in the resulting hot partially emulsified mixture from 5-15 of a water-soluble alkyl benzene sulphonate detergent the length of the alkyl chain of which is from C9 to C16, serially incorporating from 1020% of an inert filler and an aqueous suspension of from 5-15 of starch into the hot sulphonate-containing mass, raising the temperature of the mass to approximately 100 C. and dispersing from 510% of waterglass (sodium silicate) therethrough, and thereafter working up and forming the resulting product into massive form, the percentages being by weight based on the final product.

References Cited in the file of this patent UNITED STATES PATENTS 2,587,637 McDonald Mar. 4, 1952 FOREIGN PATENTS 583,028 Great Britain Dec. 5, 194-6 588,653 Great Britain May 29, 1947 592,206 Great Britain Sept. 10, 1947 OTHER REFERENCES Antwerpen-Article in News Edition of A. D. S.November 25, 1941, pp. 1255, 1256, 1258. Vol. 19, No. 22. (Copy in Sci. Lib.)

Staybelite Resin-Bulletin (8 pages), Hercules Powder Co., 1946. (Copy in Div. 63.) 

1. PROCESS PRODUCING A NON-SOAPY DETERGENT COMPOSITION IN MASSIVE FORM, WHICH COMPRISES MELTING TOGETHER, AT AN ELEVATED TEMPERATURE NOT MATERIALLY EXCEEDING 100* C., 7 TO 20 PARTS BY WEIGHT OF STEARIC ACID, 2 TO 19 PARTS BY WEIGHT OF PARAFFIN WAX HAVING A MELTING POINT LYING BETWEEN 52* AND 60* C., AND 0.5 TO 2.0 PARTS BY WEIGHT OF AN ESTER GUM, CONTINUING THE HEATING AND STIRRING UNTIL THE BUBBLE FORMATION CASES, CONTINUING THE STIRRING WITHOUT HEATING UNTIL THE MIXTURE ASSUMES A CREAMY CONSISTENCY, MATURING THE MIXTURE BY ALLOWING IT TO STAND FOR SEVERAL DAYS, PREPARING A HOT AQUEOUS SOLUTION OF FROM 2.5 TO 5.0 PARTS BY WEIGHT OF SODIUM CARBONATE, MELTING THE MATURED MIXTURE AND THROUGHLY DISPERSING THE SAME IN SAID HOT AQUEOUS SOLUTION, WITH STIRRING, GRADUALLY ADDING TO AND THOROUGHLY DISPERSING IN THE RESULTING HOT PARTIALLY EMULSIFIED MIXTURE 5 TO 15 PARTS BY WEIGHT OF A WATER-SOLUBLE ALKYL BENZENE SULPHONATE DETERGENT THE LENGTH OF THE ALKYL CHAIN OF WHICH IS FROM C9 TO C16, SERIALLY INCORPORATING 10 TO 20 PARTS BY WEIGHT OF AN INERT FILLER AND AN AQUEOUS SUSPENSION OF 5 TO 15 PARTS BY WEIGHT OF STARCH IN THE HOT SULPHONATECONTAINING MASS, RAISING THE TEMPERATURE OF THE MASS TO APPROXIMATELY 100* C. AND DISPERSING 5 TO 15 PARTS BY WEIGHT OF WATER GLASS (SODIUM SILICATE) THERETHROUGH, AND THEREAFTER WORKING UP FORMING THE RESULTING COMPOSITION INTO MASSIVE FORM. 